1. Field of the Invention
The present invention relates to load carriers and more particularly to a powered load carrier such as a wheelbarrow which is operable by an individual but is powered to permit a larger capacity to be carried and to move loads uphill.
2. Description of the Prior Art
The present invention is a modification and improvement of the device disclosed and claimed in U.S. Pat. No. 4,289,212 for a SELF PROPELLED BATTERY POWERED CART FOR PUSHING DISABLED VEHICLES issued Sept. 15, 1981, to Eric A. Immel, the inventor of the present invention, and now sold under the registered U.S. trademark "PushMobile". The device of that invention has been modified slightly as will be evident from the enclosed drawings for permitting the machine to carry materials on top of it either on a flatbed or in a bucket as well as to push-movable objects.
The closest prior art invention known to the inventor is U.S. Pat. No. 4,589,508 for a MOTORIZED WHEELBARROW issued May 20, 1986, to William A. Hoover and Fred E. Payne. That device is similar in construction to a standard wheelbarrow with a motor located underneath it which drives a single front wheel. However, the bucket of that wheelbarrow is supported in a frame which is capable of being pivoted upward and forward over the front wheel in order to empty the bed without having to lift the engine and power drive train. The problem with the device of the `508` patent is that the center of gravity of both the load and the engine are behind the front wheel and forward of the lifting handles whereby in order to move the load the operator must lift not only the load but also the engine and transmission which drive the wheelbarrow.
Not only is the motorized wheelbarrow of the `508` patent impractical because of the additional proportional weight of the engine and transmission that must be lifted when transporting a load, but the dumping of the wheelbarrow is made even more difficult than in a standard wheelbarrow. With a standard wheelbarrow, the operator lifts up on the handles which gives leverage to dump the load. But in the `508` motorized wheelbarrow, the bucket must be dumped forward over the front wheel while the motor and handles remain horizontal.
Thus, the design appears to be an entirely impractical concept as it disregards the two particular advantageous features of a traditional wheelbarrow. The reduction in weight of a particular load that needs to be lifted by the operator of a standard wheelbarrow is achieved through the leverage provided by the elongated handles and centering the load close to the wheel. This advantage is off set in the `508` patent by adding the heavy motor and transmission to the load to be lifted. Worse yet, however, is the fact that the load has to be dumped without the leverage provided by standard wheelbarrow handles since the bucket must be dumped separately without the aid of the handles which stay flat with the motor and transmission. Even more disadvantageous is the fact that the operator cannot position himself close to the bucket for the purpose of lifting it and the load but must straddle the handles and motor, or stand between them and lean over the motor, in order to obtain the best lifting advantage at the rear of the bucket. This seems to be a totally impractical design for these several reasons.
The present invention has none of the disadvantages of the `508` patent and solves all of the problems that needed to be overcome to provide a motorized load carrier. In the process of solving these problems, several important additional advantages are achieved.